Opening and cleansing of asbestos fibrous material



April 28, 19 42. w. J. ELLISON OPENING AND CLEANSING OE ASBESTOS FIBROUSMATERIAL 4 Sheets-Sheet 1 Filed Jan. 23, 1940 April 1942- w. J. ELLISON2,280,902

OPENING AND CLEANSING OF ASBESTOS FIBROUS MATERIAL Filed Jan. 25, 1940 4Sheets-Sheet 2 Fig. 2.

April as, 19429 w, Jv ELLISON 2,280,902

OPENING AND CLEANSING OF ASBESTOS FIBROUS MATERIAL;

Filed Jan. 23, 1940 4 Sheets-Sheet- 3 Fbkplf'ii s 1942 w. J. ELLISON2,280,902

OPENING AND CLEANSING OF ASBESTOS FIB ROUS MATERIAL Filegi 12x. 23, 19404 SheetsSheet 4 I vepto A ltqmey Patented Apr. 28, 1942 OPENING ANDCLEANSING or asnas'ros. rmaous MATERIAL Wilfred James Ellison, Norden,Rochdale, England, assignor to Turner and Newall Limited, Spotland,Roclidale, England, a British com- Application January 23, 1940, SerialNo. 315,191 In Great Britain November 14, 1939 (Cl. 209-2) I 17 Claims.

This invention relates to the opening of asbestos fibrous materials andtheir cleansing or separation from rock and other foreign matter. Theinvention also includes the opening of asbestos together with aproportion of other fibres of animal or vegetable origin, whereby amixture of asbestos and such other fibres is effected, in cases wherethe product desired is a mixed one. Asbestos-bearing rock when mined iscrushed to separate the fibrous matter from the rock, is screened todiscard rock particles, dirt and dust, and is then opened to separatethe constituent fibres by a variety of processes, which may includefurther crushing, beating and similar operaations, and screening toseparate the fibres from the residue. The beating machines used, evenwhen the partially separated asbestos has been carried forward by an airblast, have been of types in which the asbestos is forced against thewall of a casing or other surfaces, causing trapping and grindingactions to occur which result in deterioration of the fibres while theproduct is imperfectly separated and cleansed.

It is the principal object of the present invention to improve theseparation and cleansing of the fibrous asbestos in the openingoperation while minimising damage to the fibres due to trapping,grinding and so forth. This object is attained in the main by causingthe asbestos to travel at high speed, while freely suspended in air,through one or more casings in which beaters move at a high speed in adirection generally opposed to the travel of the asbestos at entry, theclearances and the speed of travel through the casing being such thatthe opening is eifected by impact between the material and the heaterswithout any tearing or grinding between moving and stationary members.In general, a number of successive treatments in beating machines of thecharacter indicated are required to complete the opening of the fibres,after which the fibres are separated from the dirt by centrifugal orother separators and by screening apparatus of known types.

, For insuring success in effecting the opening of the asbestos by themeans indicated above, it is necessary to subject the partially brokenasbestos material to preliminary operations which eliminate grosserimpurities and reduce the size of any lumps, while spreading thematerial out into a stream of more or less uniform consistency where itis fed to the intake of the openingapparatus. Another object of theinvention is therefore to effect the preliminary treatment and feedingof the asbestos material to the opening apparatus in such a manner as toenable this apparatus to operate as efficiently as possible.

The invention is of use not only at the mines where the asbestos-bearingrock is broken, the asbestos fibre separated from crude impurities, andprepared for transport, but also at factories where the partiallytreated asbestos is subjected to further opening and cleansing beforeits-use for commercial purposes, whether for spinning and textileproductions or for making'into such products as asbestoscement,-asbestos with rubber, or asbestos with resin products and thelike. The invention is of use also where the partially treated asbestosis to be mixed with wool, cotton or other textile fibres, in which casethe opening operation mixes the fibres together in a substantiallyuniform manner. a

In its preferred form the opening apparatus includes a number of casingsarranged in series, each containing a high speed rotary beater, thefeeding apparatus being caused to deliver a continuous stream ofpartially separated fibrous material to the inlet of the first casing,while a powerful air current induced by a fan carries this materialthrough the series of casings in each of which the beating action takesplace while the material is air-home. The beaters may consist of armsprojecting radially from an axle, and moving towards a tangentiallydirected throat through which the air blast carrying the asbestosmaterial enters the casing. From the outlet of the last casing of theseries the products are delivered toseparators such as centrifu gal orother settling apparatus, followed by screening and other apparatus, asmay be required for separating and delivering the fibrous asbestosproduct.

The invention is illustrated by way of example in the accompanyingdrawings wherein:

Figure 1 is a diagram showing a complete feeding, opening and separatingplant;

Figure 2 is a diagram showing a modified form of the feeding portion ofthe plant;

Figure 3 shows two sections of the opening apparatus to a larger scale;

Figure 4 shows a side view of part of a beater such as is used in theopening apparatus of Figure 3, and in the feeding apparatus also;

Figure 5 is an end view. and

Figure 6 is a partial side elevation of a form of paddle member used infeeding apparatus of the Figure 1 type; t

Figure '1 is an end view, and

Figure 8 is a partial side elevation of another form of paddle memberused in feeding apparatus of theFigure 2 type;

Figure 9 shows an additional form of separator which may be introducedinto the system when required.

Referring first to Figure l, the opening apparatus forming the basis ofthe invention is the set of interconnected casings 26 with a rotarybeater 21 in each. These are more fully described hereinafter withreference particularly to Figure '3. In order that their operation maybe appreciated,- however, it is desirable first to trace the path of thematerial through the complete installation, indicating its condition andhow it is fed forward at the various stages.

' A reversely rotating paddle wheel 16, whose blades may be of the typeshown in Figures 5 and 6, operates in close juxtaposition to the plateI4, and lifts up portions of the material from the plate, dropping itclear over the end of the plate into a receptacle l1 below. The lip ISon plate l4 holds back any material which may escape underneath thepaddle wheel IS. The receptacle H has a. curved bottom, and within itnear the edge of the curved plate rotates a heater [8 consisting of armsor pins projecting from an axle as indicated in Figure 4. This beaterrotates at a considerable speed, lifting portions of the fibrousmaterial and showering them down the narrowing chute IS. The showeredmaterial falls upon a more rapidly rotating beater below the entrance toa chamber 2|, distributing the material upon a conveyor belt 22 whichtravels continuously over rollers 23 along the bottom of the chamber.The belt discharges the material in a comparatively uniform andcontinuous stream over the plate 24 'upon the surface of a perforateddrum 25 which serves to deliver the fibrous portion of the material tothe inlet 28 of the opener 26, 21'. The material is drawn into the inlet28by :a strong air current entering partly through the interior of thehollow drum 25 and through the holes on its surface, and partly aroundthe edges of 1 the inlet 28.

The outlet 29 of the last section of the opener communicates with atrunk 32 leading to a centrifugal separator 30, connected to a fan 3i.This fan draws air at high velocity from around and through theperforated drum 25 and through the inlet 28, the opener casings 26 andthe trunk .32 to the separator in which the air and dust are dischargedwhile the heavier solid matter consisting of the opened asbestos, andparticles of rock and waste material, is delivered through a rotarydischarge valve 33 to a rotating screen 34. This separates the fibrousproduct from the rock and waste matter, the fibres passing over to areceptacle 35 while the solid waste and short fibres passing through thescreen drop into a hopper 36 which may discharge them upon a conveyorbelt 31 for removal.

The fibrous material to be opened, when it enters the first openercasing 26, is entirely or bunches of fibre. It is directed by the inletpassage 28 tangentially into the path of the beater arms 21 which aremoving oppositely to the incoming air current at this point. The beater27 revolves at a high speed, such as 2000 revolutions per minute, thisspeed varying ac-.

cording to the consistency of the material to be treated. It may be aslow as say 750 revolutions for some grades and well above 2000 forothers, and the speeds may be varied, the heaters in the succeedingcasings being driven at higher speeds than those through which thematerial,

to be treated first passes for example. The air current induced by thefans 3| is such that in the'inlet 28 to the first opener casing, and thecommunicating ducts or passages 38 between the following casings, theair speed is high, of the order of 1500 to 5000 feet per minute, againdepending upon the consistency of the material to be treated and thestrength of theimpact required at each blow between the beater arms andthe bunches of asbestos fibres to be opened out. the impacts between theheaters and the bunches of fibre moving at high speeds in opposite di-'rections, and there is no tearing or grinding action between relativelymoving surfaces, such as would tend to break up and reduce the length ofthe fibres. Moreover, the strength of the blow varies with the densityof the material, being stronger for the heavier bunches of unseparatedfibres which require more. opening and whose momentum is higher, whilethe impact is less and the opening action more gentle for the lighterand more separated portions of the material treated.

The invention does not depend upon the selection of any particulardimensions for the beatem 21, but a suitable dimension is of the orderof one foot in diameter and four feet in length. The casing 26 in whicheach beater works has smooth walls throughout. The clearance between thewalls and the beater arms at the top is small, say inch, up to the pointwhere the casing merges tangentially into the inlet passage 28. At theother side of the inlet passage a rounded corner is formed at 39, andthe wall of the casing comes very closeto the ends of the beater arms atthis point, the clearance being of the order of inch or less so as toform an air dividing edge where no asbestos can be trapped. From thepoint 39 onwards the clearance rapidly increases up to a maximum ofabout 7 inch at the bottom leading into the communicating passage 38between the first casing and the second. The clearance may be a littleless as the surface of the casing rises from the bottom into thepassagev 38.

The bunches of fibres struck by the beater arms near the entry of thecasing are knocked downwards by the impact and are thrown against thewall of the casing at about the region marked 40 in Figure 3, unlessthey are so light as to be air-home, and is in the form of smallishclusters carried forward by the air current without ef-'- fectivecontact with the casing. The impact with the wall of the casing at 40effectsfurther opening of the fibres. The speedof the air and airbornematter emerging from the inlet 28 ensures that the material being struckdownwards by the rods is kept away from the point 39 and no trapping ordamage to the material can occur between the ends of the rods and thepoint 39. At the lower part of their travel the beater arms are movingin the same direction as the air current, tending to pick up and impelthe The opening action depends mainly upon -Slx casings 26 in successionare shown in Figure 1, but more or less than this number may be used.depending upon the degree of opening desired. From the tangential outlet29 of the last casing in the series the air current, with the openedasbestos fibres substantially evenly distributed in it, passes upthrough the air trunk 32 leading to the centrifugal separator 30, whereany air and fine dust are discharged through the fan 3| while the fibresand other solid matter are collected and discharged through the valve 33to the rotary screen 34.

Although it is preferable to use a heater having radial arms arranged inrows, as indicated in Figure 4, and relatively staggered so that thearms lie in spiral tracks, any other convenient arrangement may beadopted. The arms are not necessarily made truly radial, but may be atany desired angle to the axle, and they are not necessarily round butmay be fiat or otherwise shaped. The form of beater illustrated istherefore to be regarded as an example only of a construction which iscapable of attaining the desired object. It is essential, however, thatthe beater should have separate arms with substantial spaces betweenthem so that the air current may pass comparatively freely between thearms in order same kind of action as occurs in the casings 26 asdescribed above, although the velocity of the falling material iscomparatively low and the speed of the beater 20 is not so high as thatof the beaters 21. he material is showered by the heater 2!) in thecasing 2|, causing it to be distributed more or less uniformly over theapron 22 from which it is dropped down over the guide plate 24 on to thesurface of the perforated drum 25. This drum may rotate at anyconvenient speed, such 'as 50 revolutions per minute, and it i at thispoint that the coarse foreign matter separated or loosened fromthe'asbestos in the feed mechanism described above, is discharged beforeit can enter the opener proper. The foreign matter may consist of hardpieces of rock or uncrushed asbestos to bear the bunches of asbestos upto the point of impact with the arms. A beater with paddle blades wouldnot serve the purpose.

Reverting now to the feed end of the machine, the operations which occurin distributing the bunches of fibres to be opened before they enter thepassage 28 at'the first opener casing require some further explanation.The projecting teeth of the slowly moving apron l2 discharge thematerial intermittently upon the inclined plate l4, and thisintermittent delivery should be converted into amore uniform stream ofmaterial before reaching the opening apparatus. feed apparatus can bemade to take a share in the preliminary opening and cleansing of thematerial. The paddle wheel I6 operating over the plate l4 turns veryslowly, at say two revolutions per minute, according to the grade ofmaterial to be treated, and its function is to lift the material as itaccumulates on the plate 14, delivering portions of it into thereceptacle II. The material carried over by the paddle wheel l6accumulates in the receptacle ll up to a level such that the beater I8is constantly coming into contact with it and lifting portions of thematerial to be thrown over into the chute IS.

The function of the beater I8 is quite different from that of the paddlewheel. It has separate beater arms, and may be of the form indicated inFigure 4, for example. It operates at a considerable speed, of the orderof say 150 revolutions per minute, and serves to lift bunches ofasbestos fibrous'material from the receptacle I1 and to throw them intoand down the chute H. The beater 20 at the inlet to the casing 2| mayalso be of the form indicated in Figure 4 and its speed of rotation maybe still higher, say of the order of 600 revolutions per minute. Ittherefore serves to some extent to open up the material by the Moreover,the i agglomerates which have escaped appropriate treatment in theearlier processes and require further crushing before they can beopened. Foreign matter also includes chips of wood, nails, and so forth.The heavier foreign bodies are thrown with sufficient momentum from theend of the conveyor 22 to drop upon a lip 4| above the inlet aperture28, whence they are removed by hand or by any suitable mechanism. A further separation occurs at the mouth of the inlet 28, where the fibresare drawn in by the air current while particles of rock and other mattertoo heavy to be lifted by the air current are carried forward by theperforated drum and deposited beneath the same. The deposited matter maybe collected and sorted, the lumps containing asbestos being sent backfor further crushing and treatment.

The feeding apparatusshown in Figure 1 is more particularly suitable fordealing with shorter grades of asbestos fibre. For the longer gradessuch as are generally used for textile purposes, the feeding apparatusmay with advantage be modified as indicated in Figure 2 for example, Thehopper ll, toothed apron l2 and paddle wheel l3 are the same as inFigure l, but the inclined Plate 43 on which the apron discharges thematerial now has no lip at its lower end and the paddle wheel 44operates differently from the paddle wheel 16. It preferably has bladeswith short projecting pins or arms at their ends, and a convenientconstruction for the purpose is that shown in Figures 7 and 8, in whichrods 45 are fitted into the axle 46 and have blades 41 attached to themon the front side in the direction of rotation, leaving only shortlengths of the rods 45 projecting. The amount of the projection may bevaried according to the grade of material treated, being greater whenthe fibres are already more opened as they are received in the feedingapparatus and shorter when the fibres are more dense. The paddle 44 isarranged at some little distance from the plate 43, say from inchupwards, and it revolves at a comparatively high speed, say 60revolutions per minute. Most of the fibre deposited on the plate 43passes under the paddle wheel 44 and falls directly over the end of theplate 43 into the narrowing chute 48 below. Some of the material mayalso be picked up by the rods and thrown over the top of the paddle. Thehigher the velocity of the paddle the less the proportion-of thematerial which can pass under it. The material slides down the surfaceof the plate 49 over which works a heater 50 of the type shown in Figure4. This may rotate at a speed of the order of 300 revolutions perminute, for example, and its rods may have a clearance of the order ofinch at their nearest approach from the surface of the plate 49. The

arated into smaller pieces.

gap alongside the beater 50, but the pieces of the material too-large topass are struck up bythe rods of the beater, and thereby generally sep-They may be thrown upwards repeatedly by the beater 50 until they aresmall enough to pass. Some of the material may also be thrown over thetop of the beater against the opposite wall of the chute t8, and theimpact may, have a further loosening effect upon the fibres. Thematerial falls upon the beater in the chamber 2| just as in theconstruction of Figure 1 and is distributed upon an apron 22, from thedelivery end of which the material falls over an inclined plate 24 uponthe rotating perforated drum 25. The air current around and through thisdrum and into the mouth of the passage 28 leading to the openingapparatus proper operates to carry forward the material in the samemanner as has been described with reference to Figure 1.

In some types of asbestos the rock particles entrained with the flbreoffer great resistance to reduction in size, and are not sumcientlyreduced on leaving the openers 28 to be separated adequately from thefibre in the screen 34. If this is the case it is desirable tointerpose, between the openers and the centrifugal separator, a rockseparator such as that illustrated in Figure 9. A box 51 is connected tothe outlet 29 from the last opener casing 26, and the air currentconveying the opened asbestos enters this box through a passage 52,being caused to impinge on a baflle plate 53 before it leaves by theoutlet 54 leading to the trunk 32. The baflle plate is hinged at itsupper. edge 55 and is adjustable in its angular which the material isrequired to be opened and cleansed before transport, and upon thepurposes to which it is to be applied. By adjustment of the speeds andsettings of the feed mechanism, the paddles and heaters, and above allby adjustment of the speed of the air current throughthe opener casings,and of the speed of the beaters in those casings, the apparatus can beregu-- lated to deal with a wide variety of raw and part 1:? preparedasbestos materials, and to eflect their cleansing and opening to anydegree normally reposition according to the consistency of the rockparticles to be separated. The rock particles which fall into the bottomof the box 5| are discharged through an air-sealed discharge valve 56.The box is air-tight except that provision is made for the entry of asmall regulated quantity of air 'quired. If the asbestos is to be mixedwith other fibres of animal or vegetable origin, such as wool or cotton,these may be introduced together with the asbestos in the feedingapparatus and subjected to the opening operation simultaneously with theasbestos, whereby the fibres may be opened and intimately mixed at thesame time.

Many modifications can be made in the details of the apparatus, the formand construction of the paddles and beaters, and so forth withoutdeparting from the scope of the invention. For example, the arms of theheaters are not necessarily straight; they may be articulated orotherwise made flexible, and of many different shapes in cross section.The opener casings are not necessarily disposed in a row in a horizontalplane as in Figure 1, but they may be arranged in any convenientrelative positions.

However the successive opener casings may be disposed, the apparatusaccording to the present invention tends to effect uniform openingthroughout the mass of fibres and opening to the required degree withoutdamage to the individual fibres, because the impacts are greater 1 andthe opening more severe when the bunches V or groups of fibres to beopened are more dense. There is no appreciable tendency to break thefibres because they'are never struck or dragged between relativelymoving elements, but are always freely suspended in air when struck byat 51, sufllcient toinsure that the asbestos fibres are not allowed tofall where the change of direction in the air current occurs on strikingthe battle plate. The opener outlet 29, the passage 52 and the separatoroutlet 54 are preferably made the full-width of the casings 26 so thatthe current of air with the opened asbestos in suspension from the lastopener casing strikes the baffle plate 53 in a shallow but wide stream.The heavy rock particles then fall out readily on impinging upon theheme plate 53, while the lighter fibrous matter, small rock particlesand short fibres are carried onwards by the air current through theoutlet M.

The amount of material discarded at the box I is regulated by adjustmentof' the angle of the baffle plate 53, and to some extent by the width ofopening at 57 through which additional air enters. The further backwardsthe plate 53 is turned, as indicated by dotted lines at 58 for example,the greater is the loss in velocity of the solid matter contained in theentering air current and the greater the proportion of solid matterdischarged on striking against the bafile plate. .It isgenerallydesirable only to remove the coarser rock particles there because thefine dust and the smaller particles are readily separated in thecentrifuge 30 and the screen 84 respectively. 1

The apparatus hereinbefore described is capable of use either at theasbestos mines, or in factories where asbestos products aremanufactured,

the heaters or when thrown against the casing walls. It will beappreciated that the material is always travelling at high velocitythrough or at both places, depending upon the degree to 7 theopenercasings so that a substantial output of opened asbestos isobtained although the amount of material in each casing 26 at any timeis comparatively small. The avoidance of any accumulation of bulkymaterial in the easings is of great importance in insuring that no partof the material isleft untreated, that the opening is effected withoutsubstantial breakage, and that the separated rock particles and otherwaste matter do not become embedded again among the opened asbestosfibres.

.I claim:

1. In the opening of fibrous asbestos material, the steps which compriseproviding the material in tufts of a size adapted to be air-borne,conveying at high velocity in air a stream of said detached tufts ofasbestos material and striking said tufts by an impact member while theyare being so conveyed and are freely suspended in air and withoutdisintegration of the material by rubbing or tearing action.

2. In the opening of fibrous asbestos material, providing themateair-borne,

members. thus subjecting said material to openfrom end ing actionconsisting solely of said impacts against said tufts while so suspended.

3. In the opening of fibrous asbestos material, the steps which compriseproviding the material in tufts of a size adapted to be air-bome,directing an airstream continuously from end to end of a casingcontaining beater members moving in and opposite to said airstream,conveying at high velocity in said airstream said tufts of asbestosmaterial against said oppositely moving members, and striking said tuftsby said members while they are being so conveyed and are freelysuspended in air without disintegration of the material by rubbing ortearing action.

4. In the opening of fibrous asbestos material, the steps which compriserotating beater members at a high speed within confining walls,independently setting up a high velocity air current within saidconfining walls in a direction substantially tangential to the movementof said rotating beater members, suspending in said air sage saidbeating elements move in a direction current detached tufts of asbestosmaterial so that said tufts, while freely suspended in said air current,are struck by said beater members, and providing between said beatermembers and said confining walls in the path of said air current anair-swept clearance sumcient to prevent disintegration of the materialby rubbing or tearing action on the tufts at said walls. v

5. In the opening of fibrous asbestos material, the steps which comprisesetting up a high velocity air stream through a casing containing beatermembers, introducing detached tufts of asbestos material into saidstream so as to be suspended therein, and striking said suspended tuftsby said beater members moving through said stream in a directionopposite thereto.

6. In the opening of fibrous asbestos material, the steps which compriseconveying tufts of asbestos material suspended in a high velocity airstream passing from end to end and while said tufts are suspended freelyin said current directing them against beating members and successivelystriking them by said members without disintegration of the material byrubbing or tearing action.

7. In the preparation of a fibrous mixture, the steps which compriseproducing a mixture of detached tufts of asbestos material with otherfibres, conveying said detached tufts and fibers at high velocitysuspended in air passing through a casing, striking said tufts andfibers by impact members while being so conveyed and without subjectionof said mixture to rubbing or tearing action, said impact members movingin a direc tion opposite to the movement of the fibers bornev by saidair.

8. In an apparatus for treating fibrous asbestos material, thecombination of a casing having imperforatewalls, a rotary beater mountedto rotate within said walls of said casing, a substantially tangentiallydisposed inlet passage on one side of said casing, a substantiallytangentially disposed outlet passage on the other side of said casing,means for setting up a current of air at high velocity through saidinlet Passage and into said casing, means for suspending asbestosmaterial in said air current passing through said casing, and means forrotating said beater in a direction such that at the inlet passage itmoves in a direction opposite to said air current.

9. In an apparatus for treating fibrous asbestos material, thecombination of a casing having imperforate walls, a rotary beater moun dto opposite to said air current.

10. In an apparatus for treating fibrous asbestos material, thecombination of a plurality of casings having imperforate walls, arotary' beater mounted to rotate within said wall of each of saidcasings, a substantially tangentially disposed inlet passage on one sideof each of i said casings, a substantially tangentially disposed outletpassage on the other side of each of said casings, said casings beingarranged in series by the connection of the outlet passage of each withthe inlet passage of the next, means external to said casings forsetting up a current of air at high velocity through said inlet passagesand casing in series, means for suspending asbestos material in said aircurent, and means for rotating said heaters in a direction such that aseach approaches the inlet passage to its casing it moves in a directionopposite to said air current.

gentially disposed inlet passage on one side of said casing, asubstantially tangentially disposed outlet passage on the other side ofsaid casing, means external to said casing for setting up a current ofair at high velocity through said inlet passage and into said casing,means for suspending asbestos material in said air current, and meansfor rotating said beater in a direction such that at the inlet passageit moves in a direction opposite to said air current, the clearancebetween said beater elements and said casing in the area between saidinlet and outlet passages being suflicie'nt to allow tufts of asbestosfibrous material to pass through without being subjected to rubbing ortearing between said beating elements and said casing.

12. In an apparatus for treating fibrous asbestos material, thecombination of a casing, a rotary beater comprising beating elementsmounted to rotate within said casing, a substantially tangentiallydisposed inlet passage on one side of said casing, a substantiallytangentially disposed outlet passage on the other side of said casing,means external to said casing for setting up a current of air at highvelocity through said inlet passage and into said casing, means forsuspending asbestos material in said air current,

and means for rotating said beater in a direction such that at the inletpassage it moves in a direction opposite to said air current, saidcasingbeing formed with a surface curved to provide a relatively smallclearance beyond said heating elements circumferentially from the Apoint at which said beating elements leave said outlet passage to saidinlet passage and said casing being formed with a smooth surface curvedto provide a relatively large clearance bestos material, the combinationof a casing having imperforate walls, a rotary beater mounted to rotatewithin said walls of said casing, a substantially tangentially disposedinlet passage on one side of said casing, a substantially tangentiallydisposed outlet passage on the other side of said casing, a fan forsetting up a current of air at high velocity through said inlet passage"and into said casing, means for suspending asbestos material in said aircurrent, means for rotating said beater in a direction such that at theinlet passage it moves in a direction oppo site to said air current, andcentrifugal separating means disposed between said fan and said outletpassage for separating said material from the air in which it issuspended.

14. In an apparatus for treating fibrous asbestos material, means foropening tufts of said material, conveyor means for delivering a uniformsupply of tufts to said opening means in a thin stream and readilycarried by an air current, and feeding means. for supplying tufts tosaid conveyor means, said feeding means comprising means for separatingthe asbestos material into small tufts, means for delivering bunches ofsaid material in a regular but intermittent flow, and beating means fortransforming said intermittent flow of bunches into a substantiallyuniform 15. In an apparatus for treatingfibrous asbestos material, meansfor striking tufts of said material suspended in a high velocity .aircurrent, an inlet passage leading to said striking means and arrangedadjacent the periphery of Y the drum, a rotary perforated drum arrangedclose to said inlet passage to said striking means, means for-deliveringtufts onto said drum, and means for setting up said air current to causeair to flow through said passage and the perforations in said drum andpick up said tufts.

16. In an apparatus for treating fibrous asbestos material, means forcausing tufts of said material to be carried in suspension in acontinuous air current, means in said air current for opening said tuftswhile so suspended, and

said opening means and carried by said air current, said separatingmeans comprising a baffle plate adjustable in an angular position in thepath of said air current and adapted to deflect massive particlesdownwards while permitting said air current to carry onward lighterparticles of said material,

17. In an apparatus for treating asbestos material, a casing formed withan inlet in one side and an outlet on the opposite side and havingimperforate walls, and rotary beating means mounted within said walls ofsaid casing, said beating means comprising an axle and a plurality ofseparate arms arranged in a series along said axle, means external tothe casing for setting up a current of air therethrough, and said casingbeing formed with a surface curved to provide a relatively smallclearance beyond said heating elements circumferentialiy from thetrailing edge of said outlet to the leading edge of said inlet and witha smooth surface curved to provide a relatively large clearance beyondsaid beating elements from the trailing edge of said inlet to theleading edge of said outlet.

' WILFRED J. ELLISON.

